| 摘要 |
In a low hydrogen type covered arc-electrode, the sources of diffusible hydrogen are kept to a low level by selecting kind of the ingredients for producing the electrodes or by baking the ingredients. In the process of the present invention, the covered arc-electrode is baked at a high temperature so as to extremely reduce the amount of the sources of diffusible hydrogen of the weld metal, while decomposition of limestone, which is one of the covering components, is prevented due to a novel baking atmosphere containing CO2. The weight ratio of Na2O/K2O in the covering is adjusted to be 1 or more, so as to keep amount of fumes.
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